Trocar device and method

ABSTRACT

A trocar assembly and associated methods are shown. Using example devices and methods shown, a surgeon may insert an obturator with a blade portion and a tube portion of a cannula into tissue such as eye tissue. In one state, the blade portions are wider than or equal to outer diameters of the tube portions. This facilitates an incision in tissue such as eye tissue that is wide enough to allow the tube portions to pass through. Because the blade portions are adapted to deform, they may be withdrawn through the inner diameter of the tube portions.

CLAIM OF PRIORITY

This application is a U.S. National Stage Filing under 35 U.S.C. 371from International Application No. PCT/US2017/027202 A1, filed on Apr.12, 2017, and published as WO 2017/180739 A1 on Oct. 19, 2017, whichclaims the benefit of priority to U.S. Provisional patent applicationSer. No. 62/321,571, filed on Apr. 12, 2016, each of which isincorporated by reference herein in its entirety.

TECHNICAL FIELD

This invention relates to devices and methods for insertion of acannula.

BACKGROUND

A number of ophthalmological procedures require insertion of a cannulainto an eye. Use of a cannula allows insertion and removal ofinstruments through a single opening, without making additionalincisions. Existing technologies for insertion of a cannula use a bladeto make an incision, however the blade is often smaller than an innerdiameter of the cannula being placed. This can lead to a less precisefit between the incision and the cannula than is desired. Improveddevices and procedures are desired to place cannulas into an eye.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-1C shows a trocar device according to the prior art.

FIG. 2 shows a trocar device according to an embodiment of theinvention.

FIG. 3A-3B shows a trocar device blade according to an embodiment of theinvention.

FIG. 4A-4C shows a trocar device blade according to an embodiment of theinvention.

FIG. 5A-5C shows a trocar device blade according to an embodiment of theinvention.

FIG. 6A-6B shows a trocar device blade according to an embodiment of theinvention.

FIG. 7 shows an example method of inserting a trocar according to anembodiment of the invention.

FIG. 8 shows another example method of inserting a trocar according toan embodiment of the invention.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, and in which is shown,by way of illustration, specific embodiments in which the invention maybe practiced. In the drawings, like numerals describe substantiallysimilar components throughout the several views. These embodiments aredescribed in sufficient detail to enable those skilled in the art topractice the invention. Other embodiments may be utilized andstructural, or logical changes, etc. may be made without departing fromthe scope of the present invention.

FIG. 1A shows an example of a cannula 100. The cannula includes a tube102 and a cap 104. FIG. 1B shows the cannula 100 when used with a trocarplacement tool 110. The obturator may be used to place the cannula 100into an eye or other cavity for use in a surgical procedure. The trocarplacement tool 110 includes an obturator 112 and a handle 116. In theexample shown, the obturator 112 includes a tip 114. In the exampleshown, the tip 114 includes a blade that is used to make an incision toplace the cannula 100. FIG. 1C shows an example with the cannula 100inserted into an eye 120. The tube portion 102 of the cannula 100 isplaced within the eye 120, while the cap portion 104 remains outside theeye 120 and butts up against an outer surface of the eye 120.

FIG. 2 shows another example of a trocar placement tool 200. In theexample of FIG. 2, the trocar placement tool 200 includes a handle 202,and a gripper 204 that may be used to hold a cannula 220. Although asingle gripper 204 is shown, two or more grippers may also be included.In the example shown, the cannula 220 is similar in size and shape tothe example cannula 100 shown in FIGS. 1A-1C. The cannula 220 is shownwith a tube portion 222 and a cap portion 224.

An obturator 210 is shown in FIG. 2 with a portion 214 that has an outerdiameter sized to fit within an inner diameter of the cannula 220. Theobturator 210 of FIG. 2 further shows a blade 212 at a tip of theobturator 210. The blade 212 is shown with a width that is wider thanthe inner diameter of the tube portion 222. In the example shown, theblade 212 further includes a width that is wider than an outer diameterof the tube portion 222 of the cannula 220. In one example, the blade212 is a flexible blade as described in examples below.

FIG. 3A shows one example of a trocar assembly 300 according to anembodiment of the invention. The trocar assembly 300 is shown in a firststate that may be used for insertion of a cannula. The trocar assembly300 includes a shaft portion 302 and a blade portion 304 of anobturator. The blade portion 304 is shown having a first width 306 in annon-deformed state. FIG. 3A further shows a tube portion 310 of acannula located around the shaft portion 302. In the first state, asillustrated in FIG. 3A, the first width 306 of the blade 304 is widerthan an inner diameter 312 of the tube portion 310. In one example inthe first state, as illustrated in FIG. 3A, the first width 306 of theblade 304 is also wider than an outer diameter 313 of the tube portion310. In one example (not shown) in the first state the first width 306of the blade 304 may be equal to an outer diameter 313 of the tubeportion 310.

In the example shown, the blade 304 includes a cut out 308 that enhancesan ability for the blade 304 to deform in a controlled manner. FIG. 3Bshows the trocar assembly 300 in a second state during removal of theobturator. The blade 304 is in a deformed state where the blade 304 nowexhibits a second width 307. As illustrated in FIG. 3B, the second widthis smaller or equal to the inner diameter 312 of the tube portion 310.Although any of a number of geometries of cut outs 308 may be used, inthe example shown in FIG. 3B, the cut out 308 deforms at a location 309to allow a wide portion of the blade 304 to deform to within the secondwidth 307.

In one example, the cut out 308 facilitates deformation of the bladeportion 304 from the first width 306 to the second width 307. Otherexamples may include a flexible blade portion 304 that does not utilizecut outs to enhance deformation, but otherwise utilizes thin bladematerial to permit deformation. In the example shown in FIG. 3B, thedeformation of the blade 304 is axial deformation. Other types ofdeformation may be used in other embodiments of the invention, asdiscussed below and shown in additional figures.

FIG. 4A shows another example of a trocar assembly 400 according to anembodiment of the invention. The trocar assembly 400 is shown in a firststate that may be used for insertion of a cannula. The trocar assembly400 includes a shaft portion 402 and a blade portion 404 of anobturator. The blade portion 404 is shown having a first width 406 in annon-deformed state. FIG. 4A further shows a tube portion 410 of acannula located around the shaft portion 402. In the first state, asillustrated in FIG. 4A, the first width 406 of the blade 404 is widerthan an inner diameter 412 of the tube portion 410. In one example inthe first state, as illustrated in FIG. 4A, the first width 406 of theblade 304 is also wider than an outer diameter 413 of the tube portion410. In one example (not shown) in the first state the first width 406of the blade 404 may be equal to an outer diameter 413 of the tubeportion 410.

In the example shown, the blade 404 includes a multiple cut outs 408that enhance an ability for the blade 404 to deform in a controlledmanner. FIG. 4B shows the trocar assembly 400 in a second state duringremoval of the obturator. The blade 404 is in a deformed state where theblade 404 now exhibits a second width 407. As illustrated in FIG. 4B,the second width is smaller or equal to the inner diameter 412 of thetube portion 410. In contrast to the example of FIGS. 3A-3B, the cutouts 408 of blade 404 facilitate flexion upwards (or downwards) out of aplane of the blade 304. FIG. 4C shows an end view of the blade 404 withportions 405 is a deformed state, flexed out of a plane of blade 404.

Similar to the example of FIGS. 3A-3B, examples of the invention are notlimited to configurations that include cut outs 408. Other examples mayinclude a flexible blade portion 404 that does not utilize cut outs toenhance deformation, but otherwise utilizes thin blade material topermit deformation.

FIG. 5A shows one example of a trocar assembly 500 with a flexible bladethat does not include a cutout according to an embodiment of theinvention. The trocar assembly 500 is shown in a first state that may beused for insertion of a cannula. The trocar assembly 500 includes ashaft portion 502 and a blade portion 504 of an obturator. The bladeportion 504 is shown having a first width 506 in an non-deformed state.End view illustration 508 also shows the non-deformed state.

FIG. 5A further shows a tube portion 510 of a cannula located around theshaft portion 502. In the first state, as illustrated in FIG. 5A, thefirst width 506 of the blade 504 is wider than an inner diameter 512 ofthe tube portion 510. In one example in the first state, as illustratedin FIG. 5A, the first width 506 of the blade 504 is also wider than anouter diameter 513 of the tube portion 510. In one example (not shown)in the first state the first width 506 of the blade 504 may be equal toan outer diameter 513 of the tube portion 510.

End view illustration 509 shows the blade 504 in a second state duringremoval of the obturator. The blade 504 is in a deformed state where theblade 504 now exhibits a second width 507. The second width 507 issmaller or equal to the inner diameter 512 of the tube portion 510. Theexample of FIGS. 5A-5C shows another example of flexion out of a planeof the blade 304. End view 509 illustrates a distributed flexinggradient across substantially all of the blade 504. The blade 504 isshown with a substantially smooth curve.

FIG. 5B shows an end view of the blade 504 that further illustrates thetube portion 510. In FIG. 5B, the blade 504 is in an non-deformed state,and the end view 508 is wider than an inner diameter 512 of the tubeportion 510. In this example the blade 504 is also wider that the outerdiameter 513 of the tube portion 510. FIG. 5C shows an end view of theblade 504 in a deformed state, flexed out of a plane of blade 504, andthe end view 509 is thinner than the inner diameter 512 of the tubeportion 510.

In operation, a surgeon may insert an obturator with a blade portionsimilar to blade portions 304, 404, and 504 and shaft portions similarto shaft portions 310, 410, and 510 into tissue such as eye tissue. Inone state, as described above, the blade portions 304, 404, and 504 arewider than or equal to outer diameters of the tube portions 310, 410,and 510. This facilitates an incision in tissue such as eye tissue thatis wide enough to allow the tube portions 310, 410, and 510 to passthrough. Because the blade portions 304, 404, and 504 are flexible, andare adapted to deform, they may be withdrawn through the inner diameterof the tube portions 310, 410, and 510.

FIGS. 6A and 6B show a trocar assembly 600 according to another exampleof the invention. The assembly 600 includes a shaft portion 602 and ablade portion 604 of an obturator. In FIG. 6A, the blade portion 604 isshown having a first width 607 in an non-deformed state. In FIGS. 6A and6B, the non-deformed state provides the first width 607 that is smalleror equal to an inner diameter 612 of a tube portion 610.

In the example of FIG. 6A, the blade portion 604 includes an internalspace 608 that is normally compressed at location 609. The compressionat location 609 allows the width 607 of the blade portion 604 to besmaller or equal to the inner diameter 612 of the tube portion 610.Although one possible configuration of a compression 609 is shown, otherlocations and/or configurations of compression features or constrictionsare within the scope of the invention.

As in other examples presented above, the blade portion 604 is aflexible blade portion. FIG. 6A further shows a dilator 650 adapted tofit within the internal space 608 within the blade portion 604. As a tip652 of the dilator 650 enters the internal space 608 of the bladeportion 604, the internal space 608 is expanded to a deformed stateshown in FIG. 6B. In FIG. 6B, with the dilator 650 inserted within theinternal space 608, the blade portion 604 is deformed or otherwiseexpanded to a second width 606. As illustrated in FIG. 6B, the secondwidth 606 of the blade 604 is wider than an inner diameter 612 of thetube portion 610. In one example, as illustrated in FIG. 6B, the secondwidth 606 of the blade 604 is also wider than an outer diameter 613 ofthe tube portion 610. In one example (not shown) the second width 606 ofthe blade 604 may be equal to an outer diameter 613 of the tube portion610.

In operation, a surgeon may insert the obturator with the blade portion604 and the shaft portion 620 inside the tube portion. Because the bladeportion is in the non-deformed state shown in FIG. 6A, the obturatorwill slide through the tube portion 610. Then the dilator 650 may beinserted into the internal space 608 of the blade portion 604. This willdeform the blade portion 604 to the second width 606 as shown in FIG.6B. Now the blade portion 604 is wider than or equal to an outerdiameter 613 of the tube portion 610. This facilitates an incision intissue such as eye tissue that is wide enough to allow the tube portion610 to pass through.

The surgeon may then remove the dilator 650 from within the blade 604 ofthe obturator. The blade 604 will once again return to the width 607that is smaller or equal to the inner diameter 612 of the tube portion610. The obturator and the blade 604 will thus be easily removed throughthe tube portion.

This procedure and the devices described allow a procedure to make awide incision as a result of the temporary increased width 606. Thisprocedure and the devices described also allow the obturator to bewithdrawn from within the tube portion 610 with a decreased width 607after making the incision.

FIG. 7 shows an example method according to one example. In operation702, a trocar assembly is pushed into a tissue, the trocar assemblyincluding a flexible blade having a width that is larger than an innerdiameter of a cannula. In operation 704, an incision is formed in thetissue wider than the inner diameter of the cannula using the flexibleblade and guiding the cannula into the tissue through the incision. Inoperation 706, the obturator and the blade are withdrawn, leaving thecannula in place. In operation 708, the flexible blade is deformed whilewithdrawing the obturator and the blade such that the deformed blade hasa width that is equal to or smaller than the inner diameter of thecannula.

FIG. 8 shows another method according to one example. In operation 802,a trocar assembly is pushed into a tissue, the trocar assembly includinga flexible blade at a tip of the obturator. In operation 804, anincision is formed in the tissue wider than the inner diameter of thecannula using the flexible blade and guiding the cannula into the tissuethrough the incision. In operation 706, a dilator is withdrawn, causingthe flexible blade to have a second width that is equal to or less thanthe inner diameter of the cannula. In operation 708, the obturator andthe blade are withdrawn, leaving the cannula in place.

To better illustrate the method and apparatuses disclosed herein, anon-limiting list of embodiments is provided here:

Example 1 includes a trocar assembly. The assembly includes a cannula,an obturator within the cannula, and a flexible blade at a tip of theobturator, the flexible blade having a width that is larger than aninner diameter of the cannula, wherein the flexible blade is adapted todeform sufficiently to allow the obturator to be withdrawn through theinner diameter of the cannula.

Example 2 includes the trocar assembly of example 1, wherein theflexible blade is substantially flat.

Example 3 includes the trocar assembly of any one of examples 1-2,wherein the width is larger than the outer diameter of the cannula.

Example 4 includes the trocar assembly of any one of examples 1-3,wherein the flexible blade is adapted to curl sufficiently to allow theobturator to be withdrawn through the inner diameter of the cannula.

Example 5 includes the trocar assembly of any one of examples 1-4,wherein the flexible blade is adapted to compress axially to allow theobturator to be withdrawn through the inner diameter of the cannula.

Example 6 includes the trocar assembly of any one of examples 1-5,wherein the flexible blade includes one or more cut outs within theblade to enhance flexing.

Example 7 includes the trocar assembly of any one of examples 1-6,wherein the flexible blade includes a central cut out within the bladeto enhance flexing.

Example 8 includes the trocar assembly of any one of examples 1-7,wherein the flexible blade includes a pair of side cut outs within theblade to enhance flexing.

Example 9 includes the trocar assembly of any one of examples 1-4,wherein the flexible blade includes a steel blade.

Example 10 includes a trocar assembly. The assembly includes a cannula,an obturator within the cannula, a flexible blade at a tip of theobturator, the flexible blade having an internal space within the blade,and a dilator adapted to fit within the internal space within the blade,wherein a first width of the blade is equal to or wider than an innerdiameter of the cannula when the dilator is inserted within the internalspace, and wherein a second width of the blade is equal to or smallerthan the inner diameter of the cannula when the dilator is removed fromthe internal space.

Example 11 includes the trocar assembly of example 10, wherein theobturator and the blade are integrally formed.

Example 12 includes the trocar assembly of any one of examples 10-11,wherein the blade is substantially flat.

Example 13 includes the trocar assembly of any one of examples 10-12,wherein the flexible blade includes a steel blade.

Example 14 includes a method of inserting a trocar. The method includespushing a trocar assembly into a tissue, the trocar assembly including acannula, an obturator within the cannula, and a flexible blade at a tipof the obturator, the flexible blade having a width that is larger thanan inner diameter of the cannula. The method also includes forming anincision in the tissue wider than the inner diameter of the cannulausing the flexible blade and guiding the cannula into the tissue throughthe incision, withdrawing the obturator and the blade, leaving thecannula in place, and deforming the flexible blade while withdrawing theobturator and the blade such that the deformed blade has a width that isequal to or smaller than the inner diameter of the cannula.

Example 15 includes the method of example 14, wherein deforming theflexible blade includes curling the flexible blade.

Example 16 includes the method of any one of examples 14-15, whereindeforming the flexible blade includes axially compressing at least aportion of the blade.

Example 17 includes a method of inserting a trocar. The method includespushing a trocar assembly into a tissue, the trocar assembly including acannula, an obturator within the cannula, a flexible blade at a tip ofthe obturator, and a dilator within the flexible blade causing theflexible blade to have a first width that is larger than an innerdiameter of the cannula. The method also includes forming an incision inthe tissue wider than the inner diameter of the cannula using theflexible blade and guiding the cannula into the tissue through theincision, withdrawing the dilator, causing the flexible blade to have asecond width that is equal to or less than the inner diameter of thecannula, and withdrawing the obturator and the blade, leaving thecannula in place.

Example 18 includes the method of example 17, wherein withdrawing thedilator includes withdrawing the dilator from an internal space withinobturator and the blade, wherein the internal space tapers to a morenarrow space within the blade.

These and other examples and features of the present infusion devices,and related methods will be set forth in part in the above detaileddescription. This overview is intended to provide non-limiting examplesof the present subject matter—it is not intended to provide an exclusiveor exhaustive explanation.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription, with each claim standing on its own as a separateembodiment, and it is contemplated that such embodiments can be combinedwith each other in various combinations or permutations. The scope ofthe invention should be determined with reference to the appendedclaims, along with the full scope of equivalents to which such claimsare entitled.

What is claimed is:
 1. A trocar assembly, comprising: a cannula; anobturator within the cannula; and a flexible blade at a tip of theobturator, the flexible blade having a width that is larger than aninner diameter of the cannula, wherein the flexible blade is adapted tocurl sufficiently to allow the obturator to be withdrawn through theinner diameter of the cannula.
 2. The trocar assembly of claim 1,wherein the flexible blade is substantially flat.
 3. The trocar assemblyof claim 1, wherein the width is larger than the outer diameter of thecannula.
 4. The trocar assembly of claim 1, wherein the flexible bladeis adapted to compress axially to allow the obturator to be withdrawnthrough the inner diameter of the cannula.
 5. The trocar assembly ofclaim 1, wherein the flexible blade includes a steel blade.
 6. A methodof inserting a trocar, comprising: pushing a trocar assembly into atissue, the trocar assembly including: a cannula; an obturator withinthe cannula; a flexible blade at a tip of the obturator, the flexibleblade having a width that is larger than an inner diameter of thecannula; forming an incision in the tissue wider than the inner diameterof the cannula using the flexible blade and guiding the cannula into thetissue through the incision; withdrawing the obturator and the blade,leaving the cannula in place; and curling the flexible blade whilewithdrawing the obturator and the blade such that the curled blade has awidth that is equal to or smaller than the inner diameter of thecannula.
 7. The method of claim 6, wherein deforming the flexible bladeincludes axially compressing at least a portion of the blade.